A comprehensive study on RSM optimization of the influencing variables on loading/releasing of ciprofloxacin onto/from magnetic iron nanoparticles

Fe3O4 MNPs were synthesized by the co-precipitation method and characterized via SEM, EDX, FTIR, XRD, VSM, TGA, and x-ray map. Its pHpzc was obtained at 5.4. The loading and releasing conditions for Ciprofloxacin (CIP) on/from Fe3O4 magnetic nanoparticles (MNPs) were optimized via response surface methodology (RSM). We found that pH was the most influential factor in the loading and releasing processes. The center point conditions for the loading were pH 7, CIP concentration of 14 ppm, adsorbent dose of 11 mg, and shaking time of 9 h, while for the release process, were pH 5.1, sample dose of 11 mg, and releasing time of 5.1 h. The optimal RSM run conditions for loading were pH: 5, CCIP: 13 ppm, dose: 7 mg, time: 20 h, and for the releasing process were pH: 2.7, dose: 11 mg, time: 7 h.